Mobile crane having a folding boom arrester device and folding boom for said crane

ABSTRACT

The present disclosure relates to a mobile crane that comprises an undercarriage having a chassis and comprises a superstructure that is rotatable about a vertical axis relative to the undercarriage and has a telescopic boom at whose tip a boom head is arranged. The boom has holding means at one side for the support of a folding boom that can be releasably installed at the boom head. The boom laterally has a console and a holding element arranged between the console and the boom head. The folding boom is pivotable about a vertical axis of the holding element for the installation at the boom head, while it is supported on the console. In accordance with the present disclosure, a first securing device is arranged in the region of the console by means of which a movement of the folding boom deviating from a pivot movement about a vertical axis can be limited. The present disclosure furthermore relates to a folding boom for a crane.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priority to German Patent Application No.10 2020 118 261.9 filed on Jul. 10, 2020. The entire contents of theabove-listed application is hereby incorporated by reference for allpurposes.

TECHNICAL FIELD

The present disclosure relates to a mobile crane and to a folding boomfor said crane.

BACKGROUND AND SUMMARY

Mobile cranes are typically adapted for driving on public roads. Specialregulations with respect to the permitted weight and the maximumpermitted dimensions (in particular height and width) of the mobilecranes apply in this sector. Different permissions are possible independence on their dimensions. The effort for applying for andobtaining exemptions also depends on the dimensions.

A mobile crane as a rule has a telescopic boom in addition to anundercarriage and a superstructure rotatably supported thereon. Withsome mobile cranes it is also customary for the crane use to install afly boom, that is also called a folding boom, at the boom head or pulleyhead arranged at the end of the boom. Particularly with smaller mobilecranes, the folding boom is frequently supported at the side of the boomduring trave in public road traffic. The mobile crane thus has greatervariability in its utilizability. It is known for this purpose tosupport the folding jib laterally at the boom by means of a plurality ofholding means, with a laterally projecting console being able to beprovided on which the folding boom is supported during storage and/orduring part of the installation procedure.

A major feature in mobile cranes having a folding boom supported at andtaken along with the boom is the moving of the folding boom from atransport position at the boom into a working position in which it isinstalled at the boom head and vice versa (also called the assembly ordisassembly of the crane). Such mobile cranes that can be traveled tothe deployment site as a completely autonomous unit and that can beassembled there are also called taxi cranes.

The assembling of the folding boom in the working position requiresvarious movements that can comprise both linear movements and movementsabout one or more typically vertical pivot axes. As a rule, however,crane actuators for these movements are only available to a limitedextent. In this respect, it can be a drive already present at the cranesuch as a telescopic cylinder or a specifically attached drive such as amanually actuated hydraulic press.

The pivot movements of the folding boom during the assembly process haveto be carried out in part at times at which no secure or completeconnection to the telescopic boom has been established due to operatingerror. The folding boom, that is supported on the console, for example,via rolls/rollers, moves along the console during the pivot movement inthis process. If operating errors occur here, the support of the foldingboom could move to the end of the console, with the folding boom's ownweight being able to result in a further unwanted movement and finallyin a sliding of the folding boom from the console. In the worst case, acomplete falling off of the folding boom is threatened.

Against this background, it is an underlying object of the presentdisclosure to further develop such a mobile crane such that the safetyduring assembly and disassembly is increased.

This object is achieved in accordance with the present disclosure by acrane that comprises an undercarriage having a chassis and asuperstructure that is rotatable about a vertical axis relative to theundercarriage and has a telescopic boom at whose tip a boom head isarranged. The boom has holding means at one side for the support of afolding boom that can be releasably installed at the boom head. The boomlaterally has a console and a holding element arranged between theconsole and the boom head. The fooling boom is pivotable about avertical axis of the holding element for the installation at the boomhead while it is supported on the console.

The forces caused by the folding boom's own weight during the movementprocedures during the assembly or disassembly are distributed by thesupport on the console and the forces acting on the holding element arereduced. The chassis can be a crawler chassis or a wheeled chassis.

In accordance with the present disclosure, a first securing device isarranged in the region of the console by means of which a movement ofthe folding boom deviating from a pivot movement about a vertical axiscan be limited.

The designation “vertical axis of the holding element” in the presentcase means that the connection between the folding boom and the boomformed by the holding element permits a pivot movement of the foldingboom about a vertical axis. A movement of the folding boom deviatingfrom a pivot movement about a vertical axis is a movement that not onlytakes place substantially in a horizontal plane, but that additionallyalso has a vertical movement component. This can in particular occurduring an improper assembly procedure due to the folding boom's ownweight on a sliding off or falling off of the folding boom.

In this respect, it is assumed in the present case that the assemblyprocedure of the folding boom takes place with a horizontally orientedboom so that the pivot axis about which the folding boom is pivoted isvertically oriented. However, the case is also covered by the presentdisclosure that the assembly/disassembly of the folding boom takes placewith a slanted boom, i.e. a not completely horizontally oriented boom.In this case, the designations “vertical axis” and “horizontal plane”are to be understood such that the pivot movement of the folding boomtakes place in a plane that is perpendicular to the pivot axis, with thepivot axis being oriented perpendicular to the longitudinal axis of theboom and being in a plane that is in parallel with the plane spanned bythe longitudinal axis and the vertical.

A sliding of the folding boom from the console on an operating error canbe prevented by the first securing device and the safety of the assemblyand disassembly procedure can thereby be increased. The case is thusalso covered by the safety system in accordance with the presentdisclosure that the folding boom is pivoted about the vertical axis ofthe holding element to join together fastening means of the folding boomand the boom head together, but a connection or pinning of the joinedtogether fastening means is forgotten and the connection of the foldingboom at the holding means is subsequently released. In this case, thefolding boom is not held by the connection of the fastening means at theboom head and there is also the risk that the folding boom will slip offfrom the console and will fall off on a use of further holding orsecuring devices. A collapse of the folding boom is effectivelyprevented in such a case by the additional securing device in the regionof the console.

Advantageous embodiments of the present disclosure result from thefollowing description.

Provision is made in an embodiment that a second securing device bymeans of which a vertical movement or falling movement of the foldingboom can be limited is arranged laterally at the boom between the firstsecuring device and the boom head. A falling down of the folding boomcan be reliably prevented even on a gross operating error by thecombination of the first and second securing devices.

Provision is made in a further embodiment that the second securingdevice comprises a securing arm that projects from the boom and that isconfigured such that the folding boom does not come into contact withthe securing arm in a transport position supported at the boom and onthe pivoting about a vertical axis. In the transport position, thesecuring arm can either be arranged beneath the folding boom or canproject between the corner bars and connection struts of the foldingboom without the folding boom being contacted. On a collapse of thefolding boom, it falls onto the securing arm so that the fallingmovement is stopped. The securing arm can furthermore have an upwardlyprojecting nose at its end spaced apart from the boom that prevents alateral sliding down of the folding boom. A horizontal movement of thefolding boom can therefore be blocked by the nose.

The second securing device alone admittedly already reduces the risk ofa collapse of the folding boom on an operating error, but does not coverall the conceivable scenarios of incorrect movements of the folding boomduring the assembly and disassembly procedure. There is thus the risk,for example, in the above-described scenario, in which a connection ofthe joined together fastening means is forgotten and the connection atthe holding element is subsequently released, that the folding boomslides off the second securing device and from the console despite thecapturing effect of said second securing device. This can only beeffectively prevented by the first securing device in accordance withthe present disclosure that is arranged in the rear region of the boom.

Provision is made in a further embodiment that the first securing deviceis arranged at the console. The first securing device is thereforeconnected to the console or to a part of the console.

Provision is made in a further embodiment that the console has afoldable structure and comprises at least two console parts that arepivotably connected to one another and are releasably latchable, withthe console being movable into an assembly position for the assembly ofthe folding boom at the boom head by unfolding from a transport positionand vice versa on the disassembly. On a pivoting of the folding boomabout the holding element, the folding boom covers relatively longdistances on the console due to the lever relationships so that saidconsole has to be formed as comparatively long during the assembly. Thefoldable design of the console enables a space-saving travel of thecrane and a support of the folding boom since it is only supported at apart of the console close to the boom in the transport position. Theconsole can be built up from two, three or an even larger number ofparts that are respectively pivotably connected to one another and arereleasably latchable.

Provision is made in a further embodiment that the console is configuredsuch that the folding boom is supported in a transport positionsupported at the boom via at least one roller on a first console partpreferably fixedly connected to the boom and such that the folding boomrolls off over the at least one roller along the upper side of theconsole on a pivot movement about the vertical axis of the holdingelement and with a console unfolded into the assembly position.

Provision is made in a further embodiment that the first securing deviceis arranged at a pivotable part of the console that forms the end pieceof the console in the assembly position and is configured such that thefolding boom does not come into contact with it in a transport positionsupported at the boom and on the pivoting about a vertical axis. Iftherefore a proper assembly procedure takes place in which the foldingboom performs a pivot movement about a vertical axis, i.e. a movementwithin a substantially horizontal plane, it does not contact the firstsecuring device. A contacting of the first securing device such that afalling off is prevented only takes place in the case of an additionalvertical movement component, in particular when the folding boom isabout to slide off from the console.

The upper side of the console facing the folding boom is preferablychamfered toward the bottom in the region of the first securing device.This can be necessary, for example, since the outer parts of the consolehave to be pivotable, while the folding boom is supported in thetransport position on an inner or first part of the console that is inparticular not movable. If the folding boom is not held on a pure orbitof movement taking place about a vertical axis by a proper fastening,the support, e.g. a roller/roll, can move onto this inclined section andcan produce an acceleration and sliding off of the folding boom. Thefirst securing device can advantageously be attached such that a rollingdown of the folding boom along this chamfered surface is allowed for,i.e. a contact of the first securing device by the folding boom onlytakes place specifically in this case.

Provision is made in a further embodiment that the first securing devicecomprises an arrester element that is in particular rod-shaped orbar-shaped and that is configured such that on a movement differing froma pivot movement about a vertical axis or on a sliding of the foldingboom from the console, an arrester hook provided at the folding boomcomes into engagement with the arrester element and blocks a furthermovement of the folding boom. The arrester hook is preferably configuredsuch that a release of the connection with the arrester element isprecluded. The arrester hook is furthermore arranged such that nocontact of the arrester element takes place on a proper setup procedure.The arrester hook can be welded or fastened in another manner, e.g. byscrews, clamps, or the like, to the folding boom, in particular to acorner bar or to a connection strut.

Provision is made in a further embodiment that the arrester elementprojects from the console at both sides, with two arrester hooks beingprovided at the folding boom that are arranged such that they come intoengagement with the arrester element on both sides of the console on asliding of the folding boom from the console. Such a symmetricalsolution is more stable and can where necessary compensate a tiltposition of the folding boom on the sliding from the console so that atleast one of the two arrester hooks comes into engagement with thecorresponding arrester element in every case. The arrester element canhere be produced in one part, for example as a single bar elementprojecting at both sides over the console, or in multiple parts, e.g. astwo separate rod elements attached to both sides of the console.

The reverse case is provided in an alternative embodiment, namely thatthe first securing device comprises at least one arrester element thatis configured such that on a movement differing from a pivot movementabout a vertical axis or on a sliding of the folding boom from theconsole, an arrester element arranged at the folding boom and inparticular of rod shape comes into engagement with the arrester hook andblocks a further movement of the folding boom. A plurality of arresterhooks can also be provided here, e.g. in a symmetrical arrangement withrespect to the console.

Provision is made in a further embodiment that the arrester element isformed by a corner bar or by a connection strut of the folding boom. Thefolding boom thereby does not have to be equipped with an additionalcomponent, which saves costs and weight.

A combination of the two aforesaid embodiments is also conceivable sothat the first securing device has both an arrester element and anarrester hook that cooperate with a corresponding arrester hook and acorresponding arrester element of the folding boom or that come intoengagement on a sliding of the folding boom from the console.

Provision is made in a further embodiment that the boom head hasfastening means for a connection with corresponding fastening means ofthe folding boom, with at least one fastening means of the folding boombeing able to be joined together with a fastening means of the boom headby pivoting the folding boom about the vertical axis of the holdingelement, with the folding boom preferably being pivotable about avertical axis of the joined together and connected fastening means afterconnecting the joined together fastening means and the release of theconnection to the holding element and with the remaining fastening meansthereby being able to be joined together. The fastening means can bepinning points or fork elements that are reversibly connectable to oneanother by pinning. The pin connections here each form a vertical axisabout which the folding boom is pivotable.

The present disclosure furthermore relates to a folding boom for acrane. In this respect, the same advantages and properties result forthe crane in accordance with the disclosure so that a repeat descriptionwill be dispensed with at this point. The above statements with respectto the possible embodiments of the folding boom with regard to the cranein accordance with the disclosure therefore apply accordingly to thefolding boom.

The folding boom in accordance with the present disclosure can inparticular have at least one roller/roll via which it is seated on theconsole and rolls off on the console during the pivoting about thevertical axis of the holding element, as described above. The foldingboom furthermore preferably has, as described above, an arrester hook oran arrester element that, on a sliding of the folding boom from theconsole differing from a pivot movement about a vertical axis comes intoengagement with a corresponding arrester element or arrester hook in theregion of the console such that a further movement of the folding boomis blocked. The folding boom can furthermore have a plurality ofmutually tiltable or pivotable parts so that a front part of theinstalled folding boom can be inclined—e.g. by means of an adjustmentcylinder.

The present disclosure furthermore relates to a crane in combinationwith a previously described folding boom.

BRIEF DESCRIPTION OF THE FIGURES

Further features, details, and advantages of the present disclosureresult from the embodiments explained in the following with reference tothe Figures. There are shown:

FIG. 1: an embodiment of the crane in accordance with the presentdisclosure with a folding boom in the transport position in a side view;

FIG. 2: a plan view of a boom and folding boom of the crane inaccordance with FIG. 1;

FIG. 3: a schematic representation of the view in accordance with FIG.2;

FIG. 4: a schematic cross-sectional view perpendicular to thelongitudinal axis through the folding boom and the boom in the region ofthe second securing device;

FIG. 5: a schematic cross-sectional view perpendicular to thelongitudinal axis through the folding boom and the boom in the region ofthe first securing device;

FIG. 6: a detail of the folding boom supported at the boom lookingtoward the console in the transport position in a perspectiverepresentation;

FIG. 7: the console in accordance with FIG. 6 with a view of its lowerside;

FIG. 8: a detail of the folding boom rolling off on the unfolded consolein a perspective view

FIG. 9: a detail of the arrester hook engaging around the arresterelement after the siding of the folding boom off from the console in aperspective view;

FIG. 10: the situation in accordance with FIG. 9 with an arrester hookin accordance with a further embodiment; and

FIG. 11: a detail of the arrester hook and the arrester element afterthe sliding of the folding boom from the console in accordance with analternative embodiment in a perspective view.

DETAILED DESCRIPTION

An embodiment of the mobile crane 10 in accordance with the presentdisclosure is shown in a side view in FIG. 1. The crane 10 has anundercarriage 12 having a four-axle wheeled chassis, a superstructure 14supported on the undercarriage 12 rotatably about a vertical axis, and atelescopic boom 16 arranged on the superstructure 14 pivotably about ahorizontal axis. A roller head or boom head 18 that has a plurality offastening means 50 that are formed as pinning points and via which afolding boom 20 can be installed at the boom as required is located atthe end of the boom 16. FIGS. 2 and 3 show the boom 16 and the foldingboom 20 in each case in a plan view (FIG. 3 in a schematic view).

The present embodiment is a so-called taxi crane 10 since the foldingboom 20 can be traveled to the deployment site with the crane 10 and canbe assembled and disassembled on site without any further externalauxiliary means. The folding boom 20 can be supported and securedlaterally at the boom 16 in a transport position (as shown in FIG. 1)for this purpose. The boom 16 has a row of holding means laterally forthis purpose. For assembly at the boom head 18, the folding boom 20likewise has a plurality of fastening means 60 formed as pinning points.In this respect, the folding boom 20 is supported in the transportposition such that the wider end having the fastening means 60 ispositioned next to the boom head 18.

The boom 16 has a holding element 24 laterally via which the foldingboom 20 is supported at the boom 16 pivotably about a vertical axis,with the folding boom 20 being secured against an unwanted pivoting inthe transport position via additional holding means not shown in anymore detail here. A console 22, on which the folding boom 20 issupported via a plurality of rolls or rollers 26, is furthermorelaterally arranged further to the rear on the boom 16 (in the directionof the support at the superstructure 14). In the region of the holdingelement 24, there is a securing arm 34 having a nose 36 that is arrangedat the end spaced apart from the boom 16, that projects upwardly, andthat is arranged and configured such that it does not come into contactwith the folding boom 20 in the transport position and on a properassembly and disassembly.

FIGS. 4 and 5 show schematic cross-sectional views of the folding boom20 and of a part of the boom 16 perpendicular to the longitudinal axisof the folding boom 20 or of the boom 16 in the region of the securingarm 34 (FIG. 4) and of the console 22 (FIG. 5). The boom 16 is drawnschematically here. As can be recognized in FIG. 4, the securing arm 34is arranged at a level at which is projects below and through the uppercorner bars and above and through the lower corner bars of the foldingboom 20. No contact therefore takes place on a lateral pivot movement ofthe folding boom. The securing arm 34 serves as an arrester device thatis intended to prevent a falling off of the folding boom 20 on anoperating error. If the folding boom 20 falls from the boom 16, it isintercepted by the securing arm 34, with the nose 35 preventing thefolding boom 20 from sliding off laterally over the securing arm 34.

On the assembly of the folding boom 20, a pivoting (for example by meansof a hydraulic cylinder) first takes place about the vertical axisformed by the holding element 34 to join together the fastening means50, 60 of the boom head 18 and the folding boom 20 in a horizontal orbitof movement and to bring them to cover one another. They aresubsequently pinned so that from this point in time onward the foldingboom 20 is securely fastened to the boom 16 and a falling off of thefolding boom 20 is no longer possible. The connection at the holdingelement 24 can now be released. In the next step, a horizontal pivotmovement of the folding boom 20 takes place about the vertical axisformed by the pin connection of the fastening means 50, 60 until thelongitudinal axes of the folding boom 20 and of the boom 16 are alignedand are thus disposed in the same planes or in parallel planes and theremaining fastening means 50, 60 are joined together. Finally, thelatter are likewise pinned. On dismantling, the reverse order of theaforesaid steps takes place.

During the pivot movement of the folding boom 20 about the holdingelement 24, the outer end of the folding boom 20 (the left end in FIG.2) moves away from the boom 16. It is guided on the console 22 in thisprocess. The rollers 26 are provided to reduce the forces. The requiredregion in which the folding boom 20 is supported on its pivot movementis relatively long due to the lever ratios. For this reason, the console22 is foldable and comprises three console parts 22′, 22″, 22′″ that areeach pivotably connected and latchable to one another.

In the transport position of the folding boom 20, the console 22 isfolded inward in a transport position to reduce the space requirement ofthe boom 16. The folding boom 20 is here supported on the first consolepart 22′ that is directly fastened to the boom 16. On the assembly ofthe folding boom 20, the console 22 is unfolded, in contrast, so thatthe console parts 22′, 22″, 22″ are linearly aligned and latched. Thefolding boom 20 can thereby roll off over the rollers 26 on the surfaceof the unfolded console 22 on the lateral pivoting. The console 22 isshown schematically in the unfolded state (assembly position) in FIG. 3.

While the securing arm 34 already provides a certain protection againsta collapse of the folding boom 20 as a consequence of improperoperation, serious operating errors are in particular not alwayssufficiently covered. A situation in which a pinning of the fasteningmeans 50, 60 joined together after a pivoting about the holding means 24is forgotten and the connection at the holding means 24 is subsequentlyreleased can thus, for example, have the result that the folding boom 20falls onto the securing arm 34 and then slides off the console 22. Itmay occur on such a movement that the folding boom 20 slides over thenose 36 and subsequently falls down due to the sloped position of thefolding boom 20 that is caused by its own weight and by the two supportpoints 22, 24.

In order also to cover the situations in which the folding boom 20slides off to the rear and to ensure a safe setup procedure even withserious operating errors, a further arrester device or securing device30 is provided in accordance with the present disclosure in the regionof the console 22. This device in accordance with the present disclosurearranged in the rear region of the boom 16 will be called a firstsecuring device 30 in the following and the secure arm 34, together withthe nose 36, arranged in the front region of the boom 16 will be calleda second securing device 32.

A first embodiment of the first securing device 30 in accordance withthe present disclosure is shown in more detail in FIGS. 6-9. The console22 is here shown in FIGS. 6 and 7 in the inwardly folded state or in thetransport position in which the two pivotable console parts 22″, 22′″contact the first console part 22′. The folding boom 20 is located atthe boom 16 in the transport position and is supported on the firstconsole part 22′ via the rollers 26. The outermost console part 22′″ ischamfered in a sloping or downward manner toward the end. This is interalia due to the fact that the outer console parts 22″, 22′″ have to befreely pivotable while the rollers 26 of the folding boom 20 aresupported on the first console part 22′. The slope of the console in itstapering region is actually due to the disassembly procedure. On thedisassembly, the operator pivots the folding boom toward the side of theboom 16. The folding boom is only held at two pins about the pivot axishere. A large lever arm that deflects the folding boom downwardly isproduced by the large outreach. The folding boom thus has to havesupport in the end phase of the pivot movement via the rollers 26 andthereby has to be raised in its transport position at the boom.

A thrust bearing in the form of a rod-shaped arrester element 40 isarranged at the outermost console part 22′″ and projects laterally(perpendicular to the longitudinal axis of the console part 22′″ in thepresent embodiment) from the console part 22′″. FIG. 8 shows theoutermost console part 22′″ in the unfolded state, i.e. the console 22is in the assembly position. On the outward pivoting of the folding boom20, the rollers 26 roll off on the unfolded console 22. On a properassembly procedure, the folding boom 20 moves in a horizontal plane onthe pivoting about a vertical axis (of the holding element 24 or of thepinning of the fastening means 50, 60). If an operating error occurs inwhich the folding boom 20 slides off to the bottom, i.e. in which themovement of the folding boom 20 has a vertical component, the firstsecuring device 30 thus provides that this unwanted movement is stoppedor blocked.

For this purpose, an arrester element in the form of a hook or of anarrester hook 42 is provided at the folding boom 20 and is welded in theembodiment shown in FIGS. 6-9 to a corner bar of the folding boom 20 inwhich in the embodiment shown in FIG. 10, in contrast, is clamped to thecorner bar by means of a clamp 44. If the rollers 26 of the folding boom20 leave the console 22, as can be seen in FIG. 8, the folding boom 20rolls down the inclined surface of the outermost console part 22′″ andaccelerates due to gravity. After leaving the console 22, the supporteffect is completely lost. The previous movement of the folding boom 20,however, is maintained so that a combined movement results with verticaland horizontal components. The locations of the arrester hook 42 and ofthe arrester element 40 are therefore selected suitably so that thearrester hook 42 of the folding boom 20 just falling down engages aroundthe arrester element 40 and the folding boom 20 is thereby “intercepted”(cf. FIGS. 9-10). On a proper assembly procedure or disassemblyprocedure, the arrester element 40 is, however, not contacted by thearrester hook 42.

The shape/contour of the arrester hook 42 is designed such that arelease of the connection to the arrester element 40 is not possible onits own. The connection between the arrester element 40 and the arresterhook 42 can optionally be configured such that energy can be reduced.This could take place by plastic deformation of the arrester element 40and/or arrester hook 42 or also via friction. A certain elasticity ofthe components would also be conceivable.

In contrast to the representation shown, a symmetrical solution is alsoconceivable. A longer arrester element 40 projecting at both sides ofthe outer console part 22′″ and two or more arrester hooks 42 at bothsides of the console 22 could thus be used. An arrester hook 40 formedeven longer on one side and the use of a plurality of arrester hooks 42on one side of the console 22 would also be conceivable. Differentpositions/inclinations of the folding boom 20 on a falling down couldthereby be taken into account and a safe interception could be ensured.

FIG. 11 shows an alternative embodiment in which an arrester hook 42′formed from two parallel metal sheets is provided at the end of theconsole 22 or as an extension of the outermost console part 22′″ and thearrester element 40′ is arranged at the folding boom 20. It can beimplemented, for example, in that—as shown in FIG. 11—one of the cornerbars of the folding boom 20 forms the arrester element 40′ and isintercepted and held on the falling down from the arrester hook 42′. Aseparate arrester element 40′ can naturally also be provided at thefolding boom 20. The location and shape of the arrester hook 42′ canalso differ from the embodiment shown in FIG. 11.

FIGS. 1-11 show example configurations with relative positioning of thevarious components. If shown directly contacting each other, or directlycoupled, then such elements may be referred to as directly contacting ordirectly coupled, respectively, at least in one example. Similarly,elements shown contiguous or adjacent to one another may be contiguousor adjacent to each other, respectively, at least in one example. As anexample, components laying in face-sharing contact with each other maybe referred to as in face-sharing contact. As another example, elementspositioned apart from each other with only a space there-between and noother components may be referred to as such, in at least one example. Asyet another example, elements shown above/below one another, at oppositesides to one another, or to the left/right of one another may bereferred to as such, relative to one another. Further, as shown in thefigures, a topmost element or point of element may be referred to as a“top” of the component and a bottommost element or point of the elementmay be referred to as a “bottom” of the component, in at least oneexample. As used herein, top/bottom, upper/lower, above/below, may berelative to a vertical axis of the figures and used to describepositioning of elements of the figures relative to one another. As such,elements shown above other elements are positioned vertically above theother elements, in one example. As yet another example, shapes of theelements depicted within the figures may be referred to as having thoseshapes (e.g., such as being circular, straight, planar, curved, rounded,chamfered, angled, or the like). Further, elements shown intersectingone another may be referred to as intersecting elements or intersectingone another, in at least one example. Further still, an element shownwithin another element or shown outside of another element may bereferred as such, in one example.

The following claims particularly point out certain combinations andsub-combinations regarded as novel and non-obvious. These claims mayrefer to “an” element or “a first” element or the equivalent thereof.Such claims should be understood to include incorporation of one or moresuch elements, neither requiring nor excluding two or more suchelements. Other combinations and sub-combinations of the disclosedfeatures, functions, elements, and/or properties may be claimed throughamendment of the present claims or through presentation of new claims inthis or a related application. Such claims, whether broader, narrower,equal, or different in scope to the original claims, also are regardedas included within the subject matter of the present disclosure.

REFERENCE NUMERAL LIST

-   10 mobile crane-   12 undercarriage-   14 superstructure-   16 boom-   18 boom head-   20 folding boom-   22 console-   22′ console part-   22″ console part-   22′″ console part-   24 holding element-   26 roller-   30 first securing device-   32 second securing device-   34 securing arm-   36 nose-   40 arrester element-   40′ arrester element (corner bar)-   42 arrester hook-   42′ arrester hook-   44 clamp-   50 fastening means boom head-   60 fastening means folding boom

1. A mobile crane comprising an undercarriage having a chassis andcomprising a superstructure rotatable about a vertical axis relative tothe undercarriage and having a telescopic boom at whose tip a boom headis arranged, wherein the telescopic boom has holding means at one sidefor supporting a folding boom that can be releasably assembled at theboom head, wherein the telescopic boom laterally has a console and aholding element arranged between the console and the boom head, andwherein the folding boom is pivotable about a vertical axis of theholding element at the boom head, while the folding boom is supported onthe console, wherein a first securing device is arranged in a region ofthe console by means of which a movement of the folding boom deviatingfrom a pivot movement about a vertical axis can be limited.
 2. The cranein accordance with claim 1, wherein a second securing device by means ofwhich a vertical movement of the folding boom can be limited is arrangedlaterally at the telescopic boom between the first securing device andthe boom head.
 3. The crane in accordance with claim 2, wherein thesecond securing device comprises a securing arm that projects from thetelescopic boom and that is configured such that the folding boom doesnot come into contact with the securing arm in a transport positionsupported at the boom and on pivoting about a vertical axis, with thesecuring arm.
 4. The crane in accordance with claim 1, wherein the firstsecuring device is arranged at the console.
 5. The crane in accordancewith claim 3, wherein that the console has a foldable structure andcomprises at least two console parts that are pivotably connected to oneanother and are releasably latchable, with the console being movableinto an assembly position for assembly of the folding boom at the boomhead by unfolding from a transport position and vice versa.
 6. The cranein accordance with claim 5, wherein the console is configured such thatthe folding boom is supported in a transport position supported at thetelescopic boom via at least one roller on a first console part and suchthat the folding boom rolls off over the at least one roller along anupper side of the console on a pivot movement about the vertical axis ofthe holding element and with a console unfolded into the assemblyposition.
 7. The crane in accordance with claim 6, wherein the firstsecuring device is arranged at a pivotable part of the console thatforms an end piece of the console in the assembly position and isconfigured such that the folding boom does not come into contact with itin a transport position supported at the telescopic boom and on thepivoting about a vertical axis, with the upper side of the consolefacing the folding boom.
 8. The crane in accordance with claim 5,wherein the first securing device comprises an arrester element that isrod-shaped and that is configured such that on a sliding from theconsole differing from a pivot movement about a vertical axis, anarrester hook provided at the folding boom comes into engagement withthe arrester element and blocks a further movement of the folding boom.9. The crane in accordance with claim 8, wherein that the arresterelement projects from the console at both sides, with two arrester hooksbeing provided at the folding boom that are arranged such that they comeinto engagement with the arrester element on both sides of the consoleon a sliding of the folding boom from the console, with the arresterelement being able to be produced in one part or in multiple parts. 10.The crane in accordance with claim 5, wherein the first securing devicecomprises at least one arrester hook that is configured such that on asliding of the folding boom from the console differing from a pivotmovement about a vertical axis, an arrester element arranged at thefolding boom.
 11. The crane in accordance with claim 10, wherein thearrester element is formed by a corner bar or by a connection strut ofthe folding boom.
 12. The crane in accordance with claim 1, wherein theboom head has fastening means for a connection with correspondingfastening means of the folding boom, with at least one fastening meansof the folding boom being able to be joined together by a fasteningmeans of the boom head by pivoting the folding boom about the verticalaxis of the holding element, with the folding boom being pivotable abouta vertical axis of the joined together and connected fastening meansafter connecting the joined together fastening means and a release ofthe connection to the holding element and with the remaining fasteningmeans thereby being able to be joined together.
 13. The crane inaccordance with claim 3 having a folding boom.
 14. The crane inaccordance with claim 13, wherein the folding boom has at least oneroller via which it is seated on the console and rolls off on theconsole during the pivoting about the vertical axis of the holdingelement, with the folding boom having an arrester hook or an arresterelement that comes into engagement with a corresponding arrester elementor arrester hook in the region of the console on a sliding of thefolding boom from the console differing from a pivot movement about avertical axis such that a further movement of the folding boom isblocked.
 15. The crane in accordance with claim 3, wherein the securingarm has an upwardly projecting nose at the end.
 16. The crane inaccordance with claim 6, wherein the first console part is fixedlyconnected to the boom.
 17. The crane in accordance with claim 7, whereinthe upper side of the console is downwardly chamfered in the region ofthe first securing device.
 18. The crane in accordance with claim 10,wherein the arrester element is being of rod shape comes into engagementwith the arrester hook and blocks a further movement of the foldingboom.